ads1115.h File Reference

TI ADS1115 16-bit ADC codec (DETWS_ENABLE_ADS1115). More...

#include <stdint.h>

Go to the source code of this file.

Classes
struct	Ads1115Gain
	Programmable-gain settings (PGA register codes; full-scale +/- range). Config field values shifted into the config word, so integer constants in a namespacing struct - cast-free. More...
struct	Ads1115DataRate
	Data-rate settings (DR register codes; samples per second). More...

Macros
#define	ADS1115_REG_CONVERSION   0x00
	conversion result register
#define	ADS1115_REG_CONFIG   0x01
	configuration register

Functions
uint16_t	ads1115_config_single (uint8_t channel, uint8_t gain, uint8_t dr)
	Build the 16-bit config word for a single-shot, single-ended reading of channel (0..3) at gain gain and data rate dr (comparator disabled). Out-of-range fields fall back to channel 0 / gain +/-2.048 V / 128 SPS.
int32_t	ads1115_raw_to_uv (int16_t raw, uint8_t gain)
	Convert a signed 16-bit sample to microvolts for gain's full-scale range.
bool	ads1115_begin (uint8_t addr)
	Initialize the I2C bus for the ADS1115 at addr.
bool	ads1115_read_raw (uint8_t channel, uint8_t gain, int16_t *raw)
	Single-shot read of channel (0..3) at gain into raw.
bool	ads1115_read_uv (uint8_t channel, uint8_t gain, int32_t *microvolts)
	Single-shot read of channel at gain, converted to microvolts in microvolts.

Detailed Description

TI ADS1115 16-bit ADC codec (DETWS_ENABLE_ADS1115).

The ADS1115 is a 4-channel 16-bit analog-to-digital converter on the I2C bus with a programmable-gain amplifier - far more resolution and range control than the ESP32's own ADC. A reading is a 16-bit config-register write (start, channel, gain, mode, data rate) followed by a 16-bit read of the conversion register; the signed result scales to a voltage by the selected gain's full-scale range.

This codec is pure and host-tested: ads1115_config_single builds the config word for a single-shot single-ended reading, and ads1115_raw_to_uv converts the signed sample to microvolts. On an ESP32 the binding writes the config, waits for the conversion, and reads it back over I2C (Wire); only that touches hardware.

A cheap solder-and-bench-test breakout: measure a battery, a potentiometer, or an analog sensor and bridge the reading onto the network.

Author

Douglas Quigg (dstroy0)

Date

2026

Definition in file ads1115.h.

Macro Definition Documentation

ADS1115_REG_CONVERSION

#define ADS1115_REG_CONVERSION   0x00

conversion result register

Definition at line 31 of file ads1115.h.

ADS1115_REG_CONFIG

#define ADS1115_REG_CONFIG   0x01

configuration register

Definition at line 32 of file ads1115.h.

Function Documentation

ads1115_config_single()

uint16_t ads1115_config_single	(	uint8_t	channel,
		uint8_t	gain,
		uint8_t	dr
	)

Build the 16-bit config word for a single-shot, single-ended reading of channel (0..3) at gain gain and data rate dr (comparator disabled). Out-of-range fields fall back to channel 0 / gain +/-2.048 V / 128 SPS.

ads1115_raw_to_uv()

int32_t ads1115_raw_to_uv	(	int16_t	raw,
		uint8_t	gain
	)

Convert a signed 16-bit sample to microvolts for gain's full-scale range.

ads1115_begin()

bool ads1115_begin

(

uint8_t

addr

)

Initialize the I2C bus for the ADS1115 at addr.

Returns

true on ESP32.

ads1115_read_raw()

bool ads1115_read_raw	(	uint8_t	channel,
		uint8_t	gain,
		int16_t *	raw
	)

Single-shot read of channel (0..3) at gain into raw.

Returns

false on error.

ads1115_read_uv()

bool ads1115_read_uv	(	uint8_t	channel,
		uint8_t	gain,
		int32_t *	microvolts
	)

Single-shot read of channel at gain, converted to microvolts in microvolts.